1. Field of the Invention
The present invention relates to an optical pickup mounted in an optical disk drive, and more particularly to a structure for supporting a lens provided in the optical pickup.
2. Description of the Related Art
An optical pickup mounted in an optical disk drive has a lens for focusing laser light onto a disk, and is provided with a drive mechanism for adjusting the tracking position and the focusing position of the lens in correspondence with the surface vibration and eccentricity of a disk. A conventional lens driving mechanism is disclosed in JP-A-7-50023 (pages 2 to 5, FIG. 1).
In this lens driving mechanism, the lens is held by a lens holder, a plurality of pairs of wires are provided to bridge the lens holder and a fixing portion which is fixed to the optical pickup, so as to support both side surfaces of the lens holder. Focusing coils and tracking coils are connected to the respective pairs of wires, magnets respectively opposing these coils are provided.
Consequently, if the respective coils are energized through the wires, electromagnetic forces are generated to allow the lens holder to move in a predetermined direction. Accordingly, it becomes possible to effect the tracking and focusing of the lens in correspondence with the drive current.
At this time, if the wire connected to the focusing coil and the wire connected to the tracking coil have the same spring constant, torsional resonance occurs. For this reason, the wires of the respective pairs are formed with different lengths so as to prevent the torsional resonance.
However, according to the above-described conventional optical pickup, the kinds of parts increase since the respective pairs of wires have different lengths. In particular, the kinds of parts further increase in a case where adjustment of not only the focusing and tracking directions but also such as the tiling direction of the lens is also carried out. For this reason, the wire management cost and the inventory cost become high, and the assembly operation becomes complex since the wires of plurality of lengths are present in mixed form. Accordingly, there has been a problem in that the cost of manufacturing the optical pickups increases.
In addition, wires of different spring constants are required for each model in order to obtain optimal operation of the optical pickup. For this reason, there has been another problem in that the kinds of wire further increase, so that the management cost and inventory cost become high.